I've got the fix.
Steps.
1. find your installation folder.
2. when you find that click your settings (in the Nexon Launcher) and click "Game Install / update"
3. Once there click "Change folder"
4. After you clicked that change the locat…
instead of turning them of i'd suggest to whitelist maplestory, that way you'd be able to keep your pc safe, i'm not such a big fan of turning firewalls and virusscanners off